USB flash disk is a portable storage device, due to the feature of plug and play of the USB interface, the USB flash disk has become a necessity in people's daily life.
In the prior art, the final assembly of the USB flash disk is completed in the factory by a specific tool, so users can only choose the type of the USB flash disk that manufacturers assembled for sale, for example, the users can only choose the USB flash disk of a fixed capacity, color, etc., and they can not choose their favorite shell according to their preferences, or can not choose the capacity of the USB flash disk according to their own use, that is, the users can not make the final assembly of the USB flash disk.